Joule Thief

[Mk1]

@gary

I usually recycle most of my part , back then i had those transistor form a printer they are made to driving step motor . I think they are dc to dc converter also. they come in matched pairs .

I did not make one from regular parts yet.

There is also the tri-cycle i made , with 3 jt at 120 degrees , i will give out more detail when we get there .

Mark



Thanks gary i will go get some Abra is not to far from here.

[jeanna]

OK I made those changes and it is better.

Plus there is another benefit.
Even though the voltage across unloaded secondary was only 1v higher, the secondary supported many more leds.

For example the other one was moderately bright with
3 leds and the voltage across them was
9.38v

On this configuration with
7 leds at about the same brightness, the voltage across them was
14.4-15.8v
If I 'stood back' and saw more of the wave, there was this enormous wave of the peaks of the waves themselves. That is what was fluctuating from 14.5-15.8v .

This configuration tuned to a different resistance for the highest voltage and just to be sure I was comparing similar circuits except for the winding, I put the resistor back to 122r and the lights went dimmer and the voltage was about the same as with the other configuration.

Therefore,

I really cannot say anything about which one is better, because if I compare the numbers with the new one with 122ohm resistor the voltage across the C-E is 5.5v

OOPS EDIT
The voltage across C-E with the BJTLed in place,
the frequency is 250khz where with the other one, the voltage was the same but the frequency was 153khz
which is why ...

The new one did tune to a higher voltage with the lower resistor, so I will stick with this. Anyway it was my idea to do this in the first place.

I like this. "doublecross = dblxx"
I think I will use this dblxx and see how many winds I can get on it and how many volts too.

Oh wait... I will remove one from each of the 4 corners first and see if that makes it sing louder. I could fit more secondary turns on it if it works.

jeanna

here is a drawing

[Mk1]

@all

concerning the mk4 it could be made from 2 pnp , you just need to reverse one of the pair of jt coil .

Also other improvements would be to link the base coil so they trigger at the same time.


Mark

[innovation_station]

nice job guys ...  i do have lots of input here ... 

but ill get to it soon

im working on my new tpu 45 bobbin unit ...


i will jump in the pool soon too

william

[jeanna]

Stprue,
Ah this has been a fun day.
I made a color (mess) over your drawing to line this up with what I did in a more relaxed form  .
It did work as it is drawn.

jeanna